diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kvm/mmu.c | 27 |
1 files changed, 17 insertions, 10 deletions
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index d07e436b7a42..1ca7164a74f1 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -3944,7 +3944,6 @@ static void kvm_mmu_remove_some_alloc_mmu_pages(struct kvm *kvm, static int mmu_shrink(struct shrinker *shrink, struct shrink_control *sc) { struct kvm *kvm; - struct kvm *kvm_freed = NULL; int nr_to_scan = sc->nr_to_scan; if (nr_to_scan == 0) @@ -3956,22 +3955,30 @@ static int mmu_shrink(struct shrinker *shrink, struct shrink_control *sc) int idx; LIST_HEAD(invalid_list); + /* + * n_used_mmu_pages is accessed without holding kvm->mmu_lock + * here. We may skip a VM instance errorneosly, but we do not + * want to shrink a VM that only started to populate its MMU + * anyway. + */ + if (kvm->arch.n_used_mmu_pages > 0) { + if (!nr_to_scan--) + break; + continue; + } + idx = srcu_read_lock(&kvm->srcu); spin_lock(&kvm->mmu_lock); - if (!kvm_freed && nr_to_scan > 0 && - kvm->arch.n_used_mmu_pages > 0) { - kvm_mmu_remove_some_alloc_mmu_pages(kvm, - &invalid_list); - kvm_freed = kvm; - } - nr_to_scan--; + kvm_mmu_remove_some_alloc_mmu_pages(kvm, &invalid_list); kvm_mmu_commit_zap_page(kvm, &invalid_list); + spin_unlock(&kvm->mmu_lock); srcu_read_unlock(&kvm->srcu, idx); + + list_move_tail(&kvm->vm_list, &vm_list); + break; } - if (kvm_freed) - list_move_tail(&kvm_freed->vm_list, &vm_list); raw_spin_unlock(&kvm_lock); |